Some sources speak of a single late Old English (ie Anglo Saxon) use of docga as a canine around 1050, but there is still no real explanation for where that came from. Steven, I think, spoke of the word appearing in Middle English (post Norman and his conquest), which is perchance a little late for 1050 but is probably a sensible description of when regular usage began.

Okay. My Middle English books say the Middle English term is "dogge," which comes from the OE "docga." This would seem to imply that the general usage Anglo-Saxon word for such an animal was thus "docga." I am not sure of where this reference comes from, whether it is a single reference, or whether it came from c. 1050 or not.

However, I still do not feel that this word (dog) is the etymological mystery as reported on QI. There are lots of Moderen English words that have an AS root. But where do any AS/OE words come from? Are they all accounted for?

Sure, we have "hound." This is similar to the Dutch (hond) or German (hund). Obviously, the French (chien) never caught on, Normans or not.

The German word for Horse is "Pferd." The Dutch word is "Paard." The French word is "cheval." None of these seem to have anything to do with the English "horse." which apparently comes from the AS "hors." Does that make the word "horse" an etymological mystery as well?

Etymology is not an exact science. Dogca, according to OED and other sources wasn't the standard OE word for dog. It was applied to just one fast and powerful breed, and has one citation, meaning it was rare. Hund was the standard word, deriving from the Germanic, and before that the Indo-European languages. What's strange about dogca (becoming dogge) is that it just appears in England, late in the OE period and over the next 400 years ousts the pan-European hund. It even gets adopted in other languages (Danish dogge, and the French for mastiff, dogue). The mystery, such as it is (and as Cabs pointed out), is just that we don't know where it arrived from, or why it became so popular. It's short and servicable, much like a good working terrier, but we don't - and probably won't - know much else about its origins.

Interestingly, perro, the Spanish for dog has a similarly obscure history.

The origin of the word 'horse' is a bit more strightforward. It comes from a Germanic root khursa- which had Norse, German and Dutch versions. This has in turn beeen linked back to the proto-Indo-European kurs- which meant 'to run' (cf 'current'). Not that anyone can prove it, of course.

Personally, I'm all for a bit of mystery. Maybe 'dog' was a Dark Age version of the 'quiz' story (bollocks but amusing see post 160). A bet to come up with a new word for man's best friend. Or just a nonsense word that had great mouth-feel and caught on...

The word 'dog' is regarded as one of the great mysteries of English etymology. For centuries, the standard English word for a canine was 'hound' or 'hund'. Suddenly, in the late Middle Ages, the word 'dog' - etymologically unrelated to any other known word - mysteriously appeared and displaced it.

This is true – though perhaps the word 'sudddenly' is a bit strong. While the word 'dog' (or 'dogca', at least) dates to late Old English ie 1050 (rather than 'late Middle English' as Stephen said) it is cited in the OED only half a dozen times before Shakespeare's time in the late 16th century. 'Hound' remained the common usage.

Stephen misremembered 'Middle Ages' as 'Middle English' – which is understandable, given that he has to memorise around 20 sides of information-rich A4 from scratch every week.

We do do retakes, of course, but if we niggled over every little thing, it would drive our patient (and exhausted) panel and audience mad. Also, sometimes the production team and the Duty Elves miss fine academic details like this. And sometimes, as the producer, I let them go.

That the ultimate etymology of 'dog' remains a mystery is the point that I guess most people will remember, and that really is the point that we were trying to make.

I was in the QI Building in Oxford last night watching the programme and one of the people there asserted that the word 'dog' comes from Finnish.

Lastly, all I can say is that QI tries its damnedest to be reliable but we certainly wouldn't claim to be anything like infallible.

Like many words in the English language, dog, has an equivalent Flemish/Dutch word - dog (strangely). As with many words that cross "national" boundaries it is difficult to say in which direction this has flowed but bearing in mind the derivation of many English words for animals - merel=blackbird (and in old English merl? I believe; pig=big (a piglet) etc etc - I think it quite likely that dog, referring to a mastiff currently, came from Anglo-Saxon to the shores of England. Around 10/11th century would be about right...

Like many words in the English language, dog, has an equivalent Flemish/Dutch word - dog (strangely).

We call every dog a "hond" (plural: honden), actually... Only certain races, such as the "Danish dog" are litterally translated by us ("Deense dog").

And 'hond' is ofcourse the same word as the English 'hound'.
Interestingly in Dutch 'hond' is the normal word for the species, while 'dog' is reserved for (very) big breeds; whereas in English this is (I think) the exact opposite. (Wouldn't call a chihuahua a 'hound' would you?)

Like many words in the English language, dog, has an equivalent Flemish/Dutch word - dog (strangely).

We call every dog a "hond" (plural: honden), actually... Only certain races, such as the "Danish dog" are litterally translated by us ("Deense dog").

And 'hond' is ofcourse the same word as the English 'hound'.
Interestingly in Dutch 'hond' is the normal word for the species, while 'dog' is reserved for (very) big breeds; whereas in English this is (I think) the exact opposite. (Wouldn't call a chihuahua a 'hound' would you?)

Bulldogs are quite small, and referred to us as "een dogske" (a little dog), while (at our dog training school at least) a Danish dog's just called "een dog".

Ahhh yeah! And then there's our irritating tendency of naming certain types of dog after famous commercials for dogfood, e.g. "Nero'kes" (Yorkshire Terriers) and "Cesarkes" (West Highland White Terriers). But I suppose we're not alone in that.

My dear friends, for the etymology of any words in English and other Germanic languages, you always must go back to the Indo-European (IE) roots, not Old/Medieval English, or Anglo-Saxon, or any other sources.
The IE /swnd/ (how it was pronounced, we just have no way of knowing) has become /sag/ in Persian, /hund/ in German, and /hound/ in English. As for the phonetic relationship between /s/ and /h/, we have linguistic evidence in the Sanskrit (Indian) /asura/ 'demon' for the Persian development of the word as /ahura/ 'god' (pronounced [a.hoo.ra]), as in the Zoroastrian Ahura Mazdā 'the wise lord; i.e., God'. And many other words in the different members of the IE family. (Just as a footnote, some of the celestial beings which were shared by the Indo-Iranian branch of the IEs, became opposite in temperament and characteristics after Indian and Iranian tribes ramified. For instance, /daeva/'s, which is benevolent entities in the Indian tradition, became malevolent in the Iranian tradition and now the word for "demon" in Persian is /div/.)
It is also very possible (and I can look for it further) that the word /dog/ and Persian /sag/ are also related. I am going to have to make sure that phonetically /s/ can become /d/ (I need some etymological evidence). I shall get back to you on that.